Electrical filter connectors for filtering electronic equipment from electromagnetic interference (EMI) and radio frequency interference (RFI) are well known in the electrical connector art. Such electrical filter connectors may utilize monolithic chip capacitors as shown in U.S. Pat. No. 4,500,159 (Hogan et al.), thick film capacitors as shown in U.S. Pat. No. 4,791,391 (Linell et al.) or ferrite materials as shown in U.S. Pat. No. 4,761,147 (Gauthier), to identify several known examples.
While there are many applications for electrical filter connectors, increasing need has developed for use of such filter connectors in telecommunications and data-processing systems. In such systems, in addition to protecting the electronic equipment against EMI and RFI interference, there is also need to protect the equipment against electrical power surges that result from electro-static discharges caused, for example, by a lightning strike. While various of the known filtering devices as identified hereinabove, have been used to provide such filtering capability, size and cost are placing further demands upon the design of such electrical filter connectors. For example, enhanced filtering effectiveness can be achieved by smaller size devices due to a short conduction path from the capacitors to the ground plane on system circuit boards. Such size demands for reduced electronic devices, including connectors, presents a difficult problem in providing a filtering device capable especially of meeting the higher voltages experienced in power surge conditions without breakdown of the filtering device. One known technique of increasing the dielectric strength of the filtered connector is to cover the capacitors with dielectric oil. Such a technique disadvantageously requires some physical constraint for containing the oil and in some instances, depending upon the type of oil used, is hazardous. Accordingly, there is present need for an electrical filter connector that includes filtering devices enabling the connector to be constructed in the desired size and to meet the higher voltage demands occasioned by power surges as well as to be cost effective in its construction for manufacture.